On solar wind speed distribution and geomagnetic activity during solar cycle 23 and the early ascending phase of solar cycle 24

This paper investigates solar wind repartition through four classes of solar events: (1) one class of quiet days (QD) caused by slow solar wind (V< 450 km/s), and three disturbed activities, where V ≥ 450 km/s, (2) recurrent wind (RW), (3) shock wind (SW), (4) fluctuating wind (FW). RW class is characterized by recurrent high solar wind extended on several solar rotations. SW class is caused by CMEs events. FW class is formed with all the un-identified events in the previous well-organized classes. We achieve this classification by using pixel diagram built with solar wind velocity. This includes the sunspot cycle 23 and the early ascending phase of sunspot cycle 24 (2009-2010). Quiet days occurred most frequently during the increasing phase of sunspot cycle (35%), while recurrent wind activity was present at solar maximum around 20% of the time, with the largest occurrence (49%) on the declining phase of the sunspot cycle. The largest percentage of shock wind events (43%) occurs around the maximum phase while fluctuating events stay fairly during the entire sunspot cycle (~27%). We also discuss current ideas about the interaction between solar wind and geomagnetic activity over sunspot cycle 23 and the early ascending phase of sunspot cycle 24. Key words: Solar wind, geomagnetic activity, solar cycle, sunspot cycle.